There is generally known an air conditioner comprising a heat pump apparatus having a compressor, a condenser, a pressure-reducing device and an evaporator.
In this type of air conditioner, the evaporator and the condenser are frequently designed to be of air-cooling type. When they are of air-cooling type, sufficient evaporating temperature cannot be achieved in an evaporator disposed outdoors under heating operation at a low outside temperature, so that there is a problem that COP (Coefficient of Performance) is remarkably reduced. In order to solve this problem, there has been hitherto proposed an air condition in which a refrigerant heater such as a burner or the like is disposed and COP is increased by heating refrigerant. Furthermore, there has been also proposed another air conditioner in which a super-cooler is equipped to increase COP under cooling operation.
However, both the cases need heat source equipment, which increases not only the initial cost, but also the running cost because a burner or the like needs combustion heat of fossil fuel.
Therefore, an object of the present invention is to provide an exhaust-heat using refrigerating system which can add the function of a refrigerant heater or super-cooler not by using any burner or the like, but by using exhaust heat.